After my last blog of 12Nov08, and starting from this issue, I would like to ask Mr. Hamashima about the mechanism of tyres. In order to create grip force, the rubber of the tread, which touches the road surface, appears to be most important.

So, I asked Mr. Hamashima to comment a little on “rubber.” Is the rubber used for racing tyres different from that used on regular tyres?” Also, I asked, “Does the rubber determine grip power?” Mr. Hamashima immediately responded, “Rubber is not the only factor that increases grip power.” I was a bit surprised, but Mr. Hamashima continued, ” The grip power of tyres depends on the total balance between rubber and the structure of tyres. No matter how much power the rubber may have to catch the road surface, if the structure of the tire is too soft, then it can not bring forth the grip power to support the machine.” I see! Not only the rubber itself, but also the balance between structure and rubber determine grip power. 

He continues, ” However, the performance of rubber is, of course, important for the requirement of grip. Moreover, the rubber used for regular tires used on public roads is basically the same as that used for racing tyres.” So then, what is the difference? “Rubber used for tires generally contains carbon and oil (mechanical oil = spindle oil), and the hardness or softness of the rubber will be determined by the amount of these two ingredients. When compared with regular tyres, the rubber of racing tyres contains more carbon and oil. Yet, this is not enough to keep the rubber from becoming loose. Therefore, sulfur is added to make the rubber steadier.

Explained simply, just imagine when one is making soba noodles. If 100% soba powder is used, it is too dry, so flour is added as a thickener in order to knead the soba dough. Sulfur acts as the flour in the case of making tires. ?It is interesting that rubber for tyres requires a thickener. Even more interesting was that “Rubber is matured after rubber; carbon; oil and sulfur are mixed together and kneaded. Of course it differs depending on the quantity of each ingredient, but approximately, the rubber must be set for about 1/2 day and one has to wait for it to mature.” So, within this process of maturity, rubber, carbon and oil are completely mixed and combined together by sulfur in terms of molecules. In addition to the example of soba noodles making, one must wait until rubber of tyres is matured, just like one has to do so until dough is fermented when making good bread. This was totally new to me. 

I hope you have enjoyed this issue, In the next issue we will discuss the physical structure of tyres as I had mentioned in this article earlier. So stay tuned my faithful readers.

Oh Yes!!!, In parting I leave you with a MONEY SAVING OFFER that you will not be able to resist. Bye for now.